import sys
import pytest

sys.path.insert(0, ".")
from validators import _validate_target, _validate_selection, _validate_sources


class TestValidateTarget:
    def test_empty_string_raises(self):
        with pytest.raises(Exception):
            _validate_target("")

    def test_null_string_raises(self):
        with pytest.raises(Exception):
            _validate_target("null")

    def test_whitespace_only_raises(self):
        with pytest.raises(Exception):
            _validate_target("   ")

    def test_valid_string_does_not_raise(self):
        _validate_target("data:image/jpeg;base64,abc")


class TestValidateSelection:
    def test_empty_list_raises(self):
        with pytest.raises(Exception):
            _validate_selection([])

    def test_non_empty_does_not_raise(self):
        _validate_selection([0])
        _validate_selection([0, 2, 5])


class TestValidateSources:
    def test_missing_source_raises(self):
        with pytest.raises(Exception):
            _validate_sources([0, 1], {"0": "data:..."})

    def test_empty_source_raises(self):
        with pytest.raises(Exception):
            _validate_sources([0], {"0": ""})

    def test_all_present_does_not_raise(self):
        _validate_sources([0, 1], {"0": "data:...", "1": "data:..."})

    def test_none_selected_does_not_raise(self):
        _validate_sources([], {})